1. Technical Field
The present invention relates to a liquid jet head for jetting liquid from nozzles to record an image or text on a recording medium, a liquid jet recording apparatus, and a method of filling a liquid jet head with liquid.
2. Background Art
Generally, a liquid jet recording apparatus, for example, an ink jet printer which carries out various kinds of printing, includes a transfer apparatus for transferring a recording medium and an ink jet head. As an ink jet head used here, there is known an ink jet head including a nozzle body (jetting body) having a nozzle column (jetting hole column) formed of a plurality of nozzle holes (jetting holes), a plurality of pressure generating chambers which are paired with and communicate with the nozzle holes, respectively, an ink supply system for supplying ink to the pressure generating chambers, and a piezoelectric actuator disposed adjacent to the pressure generating chambers, in which the piezoelectric actuator is driven to pressurize the pressure generating chambers to cause ink in the pressure generating chambers to be jetted from nozzles in the nozzle holes.
As a kind of such an ink jet printer, there is known an ink jet printer in which a carriage for moving the ink jet head in a direction orthogonal to the direction of transfer of recording paper (recording medium) is provided and printing is carried out on the recording paper. In an inkjet printer of such a kind, a service station for maintenance is provided in a movable range of the ink jet head, and the ink jet head is moved to the service station at which the nozzle holes are cleaned and the ink jet head is capped and sucked under negative pressure to initially fill the nozzle holes with ink (so-called suction filling). For example, Patent Documents 1 and 2 described below disclose a structure in which ink in ink orifices of a recording head is sucked by a suction pump connected to a cap under a state in which the recording head and the cap are in abutment with each other.
Further, an ink jet printer of a kind which is different from the kind of the above-mentioned ink jet printer is used for a relatively large-sized recording medium such as a box and carries out printing on a recording medium which is transferred with an ink jet head being fixed. In an ink jet printer of this kind, the ink jet head cannot be moved, and there is not enough space for providing a service station between the ink jet head and a recording medium or below the ink jet head. Therefore, when the pressure generating chambers are initially filled with ink, ink is normally pressurized from the ink supply system side during being filled.
In this pressure-filling, in order to prevent contamination of the ink jet head and of places in proximity to the ink jet printer with excess ink which droops from the nozzle holes, and in order to prevent unstable jetting of ink after the filling of the ink, it is necessary to take measures of removing excess ink. As such measures, for example, as described in Patent Document 2, a structure is disclosed in which an ink guide member that is formed of a plate-like porous absorber and protrudes outward from a nozzle formation surface and a block-shaped ink absorber connected to the ink guide member are provided below the ink jet head, excess ink is received and guided to the ink absorber by the ink guide member, and the guided excess ink is absorbed by the ink absorber.    Patent Document 1: JP 06-218938 A    Patent Document 2: JP 05-116338 A
However, in the structure disclosed in Patent Document 2, there is a problem in that space below the inkjet head may not be effectively used because the ink guide member and the ink absorber are provided below the ink jet head. Another problem is in that, therefore, printing cannot be carried out on a lower portion of a recording medium. Still another problem is in that places around the head become dirty because the ability to collect excess ink is insufficient.
The present invention has been made in view of the above, and objects of the present invention are as follows:    (1) to improve a space factor of a liquid jet head to improve flexibility in designing a liquid jet recording apparatus; and    (2) to improve ability to collect excess liquid with a simple structure to prevent contamination with excess liquid and to achieve initial filling of a liquid jet recording apparatus, to thereby stabilize jetting of liquid after the liquid is filled.